Many contractors quote price per square foot price estimates. But what you really need is a individual quote for your particular specs.
Both ways, there is no guarantee that the numbers will not change once the job starts and the walls are opened up to discover some unforeseeable issue.
But for sure a price per square foot estimate from a contractor is going to be an over estimate, but you will not see the savings, they will never admit that it was not as bad as expected. But that said when they find an unexpected condition, it will be billed as an extra!
Each building is different; get a thorough engineer inspection report and get quotes from contractors for a written list of specs required.
Over the years I have been through many buildings with many customers and their contractors, the variation of prices, estimates and quotes for the same job is as various as a Benjamin Moore paint chart!.
The ones that come in and quickly quote a price per square foot are generally the highest prices and end up with a very generic, no accounting for individual detail etc. jobs. IE Condo developments.
Please feel free to call me, if I can be of further assistance.
Kathryn Lilly, Broker
Realty on the Greene, LLC